Sewing-machine take-up mechanism



R. K. HOHMANN.

SEWING MACHINE TAKE-UP ME .NISMl APPLICATION FILED AUG.25, 9 9.1,393,127. Patented Oct. 1%1H,E U1$')21.l

2 SHEETS- I n. K. HOHMANN. SEWING MACHINE TAKE-UP MECHANISM.

APPLICATION FILED AU.G.25, I9I9- Panted 001. 11, 1921.

`2 SHEETS-SHEET z. fr. .5.

UNITED sTAras FATENT OFFICE.

RIGIIARD'ILIIOHMANN, orY PERU, INDIANA, essie-Non To HOIIMANN SEWING f..MACHINE COMPANY, or annu, INDIANA.

` i l SEWING-MACHINE Tann-U1? MEcIIANIsM'.

To all 11i/tom t mafz/ concern 'Be it known that I, RICHARD K. Horr-MANN, a citizenof the United States, and residing at Peru, Miami county,State of Indiana, have invented certain new and use- Vful Improvementsin Sewing-Machine Take- Up l\/Iechanism, Yof which the Afollowing is aspecification.

The present invention relates to sewing machines and more particularlyto take-up mechanisms for family machines employing large rotary hookmechanism.

The obj eets of the invention are to provide a smooth actingvibrationless take-up having a throw su'liicient to draw up the loopformed by the hook mechanism, said loop being relatively large becausethe rotary hook mechanism carries a bobbin larger than heretofore; andto provide a compact and simple mechanism adapted to be manufactured atminimum cost and easily assembled in the machine. Other objects andfeatures of novelty will be apparent from the description taken inconnection with the drawings in which- Figure 1 is a front elevation ofthe head end ofa sewing machine frame equipped with the presentinvention, the head being shown in section; l

Fig. 2 is a side elevation of the parts shown in Fig. l, the usual coverplate onthe head being removed;

Fig. 3 is a similar view, the parts being shown in a dierent position;and

Fig. 4 is a sectional view of a detail taken substantially on the line 44 of Fig. 2.

Referring to the drawings the numeral 10 indicates the frame of a sewingmachine having the hollow head 11 within which is disposed the takeupmechanism and the means for operating the needle bar. As shown the mainshaft 12 has a disk 13 within the hollow head, portions of which are cutaway in order to balance the same. This disk has a crank pin 14projecting from its face adapted to operate the take-up mechanism aswill be described hereinafter. Secured to the end of the crank pin 14 isan arm 15 disposed in a plane transverse to the axis of theshaft 12 andhaving at its free end a crank pin 16 parallel to the pin 14 anddisposed with its axis offset from the aXis of the shaft 12. A needlebar 17 eX- tends through the head having bearings in Specification ofLetters Patent. y Patented 001;, 11, 1921 Application filed August 25,`1919. Serial No. 319,723.

the top and bottom thereof and is operated by a link 18 having one endpivoted on the crank `pin 16 and the other end pivotally secured to theneedle bar by. a pin 19. It will be apparent therefore'that rotation ofthe shaft 12 effects reciprocation` of the needle. bar 17. y y.

The take-up mechanism of the present invention includes a rock shaft 2Odisposed with its axis parallel to the aXis of the shaft 12 and in therear of the needle bar 17 and the presser foot bar 21. In the form ofthe invention shown the rock shaft 2O consists of a sleeve rotatablymounted on a pin 22 secured in the head 11 of the machine. At one endthe rock shaft is provided with a radially projecting lug 23 and astraight bar or arm 24 is secured in the lug as by means of a set screw25. This arm has a pivotal and sliding connection with the crank pin 14.As shown, a block 26 is pivotally mounted lonthe pin 14 and this blockis formed with a bore 27 transverse to the axis of the pin 14, the bar24 slidingly fitting within the bore 27. Thus as the shaft 12 is rotatedthe rock shaft 20 is oseillated through the arm 24. Furthermore, thisconnection is absolutely noiseless and vibrationless at the speeds offamily machines. 'Ihe 'arm 24 is straight thus eliminating the shocks,noise and vibration due to employing irregular cams and other similarconneotions between the main shaft and the take-up mechanism. A take-uparm 28 is secured to the rock shaft 20 for rotation therewith and isdisposed at the left of the needle bar as viewed in Fig. 1, that is tosay, at the side ofthe needle bar opposite the actuating arm 24. Thehead 11 is formed with a suitable slot 29 through which the takeup arm28 projects.

In Fig. 2 the take-up arm 28 is shown at the upper limit of its motion,and in Fig. 3 at the lower end of its stroke. It will be observed thatthis armV moves from Sthe lower to the upper end of its stroke, that is,from the position shown in Fig. 8 to that shown in Fig. 2 while the mainshaft is turning through about 90, and thus gives a rapid take-up of thethread loop from the hook mechanism. l/Vhile at the lower end of itsstroke, the arrangement is such, that the arm 28 has a substantial dwellor period of practically no movement. This take-up mism mangaring: .vx

frame with a hollow head, a main shaft,v a

needle bar reciprocable in two bearings in the head a rock shaftdisposed parallel to the .main shaft in rear of the needle bar, a crankpin on the main shaft at the right of the needle bar, a straightactuating arm movable with the rock shaftya block rota-r tably mountedon-'said crank pin having a bore Yoii'set Jfrom, and transverse to, thecrank pin axis, said arm slidably ittedinIsaid bore, a take-uplarmsecured to the rock shaftV projecting in front vof the head and atthe left'of the needle bar, an arm carried'by said pin disposedtangentially -to a circle about the axis of said shaft, a second crankpincarried by said arm eccentrically to the axis of the main shaft andsubstantially 909 from the rstpin, anda, link connecting the lattercrank pin and needle bar, sadilink movable in a vertical plane betweenthe ac# tuating arm and needle bar.`

In testimony whereof I aiiix my signature.

RICHARD K. Hoinnnvr.;y

